An evaluation of outcome measures used in humanistic psychotherapy research: Using thermometers to weigh oranges

The establishment of treatment orientations’ efficacy has gained increasing importance. However, humanistic psychotherapists may be at a disadvantage in this endeavor. This research examined the outcome measures that have been most commonly used in the evaluation of humanistic psychotherapies. First, a theme analysis was conducted to generate a list of constructs that reflect humanistic psychotherapy progress. Subsequently, 148 nonredundant items were identified and organized by theme. Then, a content analysis of the outcome measures was conducted to evaluate their assessment of humanistic goals. Results suggest that these measures do not assess central humanistic concepts and that the process of using them to assess humanistic approaches is akin to weighing oranges with thermometers. Findings are discussed with reference to the issue of power in meta-analyses and the need to develop therapy-congruent measures of outcome.